Ultra-high-Q waveguide ring resonators for resonant integrated optical gyroscopes

: Improving the performance of the Resonant Integrated Optical Gyroscope (RIOG) relies on enhancing the quality factor ( Q ) of the waveguide ring resonator (WRR) and reducing system noise. In this work, we proposed and demonstrated ultra-high-Q silicon nitride (Si 3 N 4 ) racetrack resonators with a thickness of 400 nm, fabricated using a subtractive etching process. The add-drop resonator with the area of 32 mm 2 achieves an impressive intrinsic Q of 1.5×10 7 , corresponding to an ultralow propagation loss of only 0.023 dB/cm. The resonator was integrated into a gyroscopic system driven by a broadband light source, successfully demonstrated the gyroscopic effect and exhibited long-term bias instability (10 hours) of 10.92 °/h and an angle random walk (ARW) of 3.79 °/ at room temperature. These results will further advance the development of RIOG technology.